/* LzmaDec.c -- LZMA Decoder
2018-07-04 : Igor Pavlov : Public domain */

#include "Precomp.h"

#include <string.h>

/* #include "CpuArch.h" */
#include "LzmaDec.h"

#define kNumTopBits 24
#define kTopValue ((UInt32)1 << kNumTopBits)

#define kNumBitModelTotalBits 11
#define kBitModelTotal (1 << kNumBitModelTotalBits)
#define kNumMoveBits 5

#define RC_INIT_SIZE 5

#define NORMALIZE if (range < kTopValue) { range <<= 8; code = (code << 8) | (*buf++); }

#define IF_BIT_0(p) ttt = *(p); NORMALIZE; bound = (range >> kNumBitModelTotalBits) * (UInt32)ttt; if (code < bound)
#define UPDATE_0(p) range = bound; *(p) = (CLzmaProb)(ttt + ((kBitModelTotal - ttt) >> kNumMoveBits));
#define UPDATE_1(p) range -= bound; code -= bound; *(p) = (CLzmaProb)(ttt - (ttt >> kNumMoveBits));
#define GET_BIT2(p, i, A0, A1) IF_BIT_0(p) \
  { UPDATE_0(p); i = (i + i); A0; } else \
  { UPDATE_1(p); i = (i + i) + 1; A1; }

#define TREE_GET_BIT(probs, i) { GET_BIT2(probs + i, i, ;, ;); }

#define REV_BIT(p, i, A0, A1) IF_BIT_0(p + i) \
  { UPDATE_0(p + i); A0; } else \
  { UPDATE_1(p + i); A1; }
#define REV_BIT_VAR(  p, i, m) REV_BIT(p, i, i += m; m += m, m += m; i += m; )
#define REV_BIT_CONST(p, i, m) REV_BIT(p, i, i += m;       , i += m * 2; )
#define REV_BIT_LAST( p, i, m) REV_BIT(p, i, i -= m        , ; )

#define TREE_DECODE(probs, limit, i) \
  { i = 1; do { TREE_GET_BIT(probs, i); } while (i < limit); i -= limit; }

/* #define _LZMA_SIZE_OPT */

#ifdef _LZMA_SIZE_OPT
#define TREE_6_DECODE(probs, i) TREE_DECODE(probs, (1 << 6), i)
#else
#define TREE_6_DECODE(probs, i) \
  { i = 1; \
  TREE_GET_BIT(probs, i); \
  TREE_GET_BIT(probs, i); \
  TREE_GET_BIT(probs, i); \
  TREE_GET_BIT(probs, i); \
  TREE_GET_BIT(probs, i); \
  TREE_GET_BIT(probs, i); \
  i -= 0x40; }
#endif

#define NORMAL_LITER_DEC TREE_GET_BIT(prob, symbol)
#define MATCHED_LITER_DEC \
  matchByte += matchByte; \
  bit = offs; \
  offs &= matchByte; \
  probLit = prob + (offs + bit + symbol); \
  GET_BIT2(probLit, symbol, offs ^= bit; , ;)



#define NORMALIZE_CHECK if (range < kTopValue) { if (buf >= bufLimit) return DUMMY_ERROR; range <<= 8; code = (code << 8) | (*buf++); }

#define IF_BIT_0_CHECK(p) ttt = *(p); NORMALIZE_CHECK; bound = (range >> kNumBitModelTotalBits) * (UInt32)ttt; if (code < bound)
#define UPDATE_0_CHECK range = bound;
#define UPDATE_1_CHECK range -= bound; code -= bound;
#define GET_BIT2_CHECK(p, i, A0, A1) IF_BIT_0_CHECK(p) \
  { UPDATE_0_CHECK; i = (i + i); A0; } else \
  { UPDATE_1_CHECK; i = (i + i) + 1; A1; }
#define GET_BIT_CHECK(p, i) GET_BIT2_CHECK(p, i, ; , ;)
#define TREE_DECODE_CHECK(probs, limit, i) \
  { i = 1; do { GET_BIT_CHECK(probs + i, i) } while (i < limit); i -= limit; }


#define REV_BIT_CHECK(p, i, m) IF_BIT_0_CHECK(p + i) \
  { UPDATE_0_CHECK; i += m; m += m; } else \
  { UPDATE_1_CHECK; m += m; i += m; }


#define kNumPosBitsMax 4
#define kNumPosStatesMax (1 << kNumPosBitsMax)

#define kLenNumLowBits 3
#define kLenNumLowSymbols (1 << kLenNumLowBits)
#define kLenNumHighBits 8
#define kLenNumHighSymbols (1 << kLenNumHighBits)

#define LenLow 0
#define LenHigh (LenLow + 2 * (kNumPosStatesMax << kLenNumLowBits))
#define kNumLenProbs (LenHigh + kLenNumHighSymbols)

#define LenChoice LenLow
#define LenChoice2 (LenLow + (1 << kLenNumLowBits))

#define kNumStates 12
#define kNumStates2 16
#define kNumLitStates 7

#define kStartPosModelIndex 4
#define kEndPosModelIndex 14
#define kNumFullDistances (1 << (kEndPosModelIndex >> 1))

#define kNumPosSlotBits 6
#define kNumLenToPosStates 4

#define kNumAlignBits 4
#define kAlignTableSize (1 << kNumAlignBits)

#define kMatchMinLen 2
#define kMatchSpecLenStart (kMatchMinLen + kLenNumLowSymbols * 2 + kLenNumHighSymbols)

/* External ASM code needs same CLzmaProb array layout. So don't change it. */

/* (probs_1664) is faster and better for code size at some platforms */
/*
#ifdef MY_CPU_X86_OR_AMD64
 */
#define kStartOffset 1664
#define GET_PROBS p->probs_1664
/*
#define GET_PROBS p->probs + kStartOffset
#else
#define kStartOffset 0
#define GET_PROBS p->probs
#endif
 */

#define SpecPos (-kStartOffset)
#define IsRep0Long (SpecPos + kNumFullDistances)
#define RepLenCoder (IsRep0Long + (kNumStates2 << kNumPosBitsMax))
#define LenCoder (RepLenCoder + kNumLenProbs)
#define IsMatch (LenCoder + kNumLenProbs)
#define Align (IsMatch + (kNumStates2 << kNumPosBitsMax))
#define IsRep (Align + kAlignTableSize)
#define IsRepG0 (IsRep + kNumStates)
#define IsRepG1 (IsRepG0 + kNumStates)
#define IsRepG2 (IsRepG1 + kNumStates)
#define PosSlot (IsRepG2 + kNumStates)
#define Literal (PosSlot + (kNumLenToPosStates << kNumPosSlotBits))
#define NUM_BASE_PROBS (Literal + kStartOffset)

#if Align != 0 && kStartOffset != 0
#error Stop_Compiling_Bad_LZMA_kAlign
#endif

#if NUM_BASE_PROBS != 1984
#error Stop_Compiling_Bad_LZMA_PROBS
#endif


#define LZMA_LIT_SIZE 0x300

#define LzmaProps_GetNumProbs(p) (NUM_BASE_PROBS + ((UInt32)LZMA_LIT_SIZE << ((p)->lc + (p)->lp)))


#define CALC_POS_STATE(processedPos, pbMask) (((processedPos) & (pbMask)) << 4)
#define COMBINED_PS_STATE (posState + state)
#define GET_LEN_STATE (posState)

#define LZMA_DIC_MIN (1 << 12)

/*
p->remainLen : shows status of LZMA decoder:
    < kMatchSpecLenStart : normal remain
    = kMatchSpecLenStart : finished
    = kMatchSpecLenStart + 1 : need init range coder
    = kMatchSpecLenStart + 2 : need init range coder and state
 */

/* ---------- LZMA_DECODE_REAL ---------- */
/*
LzmaDec_DecodeReal_3() can be implemented in external ASM file.
3 - is the code compatibility version of that function for check at link time.
 */

#define LZMA_DECODE_REAL LzmaDec_DecodeReal_3

/*
LZMA_DECODE_REAL()
In:
  RangeCoder is normalized
  if (p->dicPos == limit)
  {
    LzmaDec_TryDummy() was called before to exclude LITERAL and MATCH-REP cases.
    So first symbol can be only MATCH-NON-REP. And if that MATCH-NON-REP symbol
    is not END_OF_PAYALOAD_MARKER, then function returns error code.
  }

Processing:
  first LZMA symbol will be decoded in any case
  All checks for limits are at the end of main loop,
  It will decode new LZMA-symbols while (p->buf < bufLimit && dicPos < limit),
  RangeCoder is still without last normalization when (p->buf < bufLimit) is being checked.

Out:
  RangeCoder is normalized
  Result:
    SZ_OK - OK
    SZ_ERROR_DATA - Error
  p->remainLen:
    < kMatchSpecLenStart : normal remain
    = kMatchSpecLenStart : finished
 */


#ifdef _LZMA_DEC_OPT

int MY_FAST_CALL LZMA_DECODE_REAL(CLzmaDec *p, SizeT limit, const Byte *bufLimit);

#else

static
int MY_FAST_CALL LZMA_DECODE_REAL(CLzmaDec *p, SizeT limit, const Byte *bufLimit)
{
    CLzmaProb *probs = GET_PROBS;
    unsigned state = (unsigned) p->state;
    UInt32 rep0 = p->reps[0], rep1 = p->reps[1], rep2 = p->reps[2], rep3 = p->reps[3];
    unsigned pbMask = ((unsigned) 1 << (p->prop.pb)) - 1;
    unsigned lc = p->prop.lc;
    unsigned lpMask = ((unsigned) 0x100 << p->prop.lp) - ((unsigned) 0x100 >> lc);

    Byte *dic = p->dic;
    SizeT dicBufSize = p->dicBufSize;
    SizeT dicPos = p->dicPos;

    UInt32 processedPos = p->processedPos;
    UInt32 checkDicSize = p->checkDicSize;
    unsigned len = 0;

    const Byte *buf = p->buf;
    UInt32 range = p->range;
    UInt32 code = p->code;

    do
    {
        CLzmaProb *prob;
        UInt32 bound;
        unsigned ttt;
        unsigned posState = CALC_POS_STATE(processedPos, pbMask);

        prob = probs + IsMatch + COMBINED_PS_STATE;

        IF_BIT_0(prob)
        {
            unsigned symbol;
            UPDATE_0(prob);
            prob = probs + Literal;
            if (processedPos != 0 || checkDicSize != 0)
                prob += (UInt32) 3 * ((((processedPos << 8) + dic[(dicPos == 0 ? dicBufSize : dicPos) - 1]) & lpMask) << lc);
            processedPos++;

            if (state < kNumLitStates)
            {
                state -= (state < 4) ? state : 3;
                symbol = 1;
#ifdef _LZMA_SIZE_OPT
                do
                {
                    NORMAL_LITER_DEC
                }
                while (symbol < 0x100);
#else
                NORMAL_LITER_DEC
                NORMAL_LITER_DEC
                NORMAL_LITER_DEC
                NORMAL_LITER_DEC
                NORMAL_LITER_DEC
                NORMAL_LITER_DEC
                NORMAL_LITER_DEC
                NORMAL_LITER_DEC
#endif
            }
            else
            {
                unsigned matchByte = dic[dicPos - rep0 + (dicPos < rep0 ? dicBufSize : 0)];
                unsigned offs = 0x100;
                state -= (state < 10) ? 3 : 6;
                symbol = 1;
#ifdef _LZMA_SIZE_OPT
                do
                {
                    unsigned bit;
                    CLzmaProb *probLit;
                    MATCHED_LITER_DEC
                }
                while (symbol < 0x100);
#else
                {
                    unsigned bit;
                    CLzmaProb *probLit;
                    MATCHED_LITER_DEC
                    MATCHED_LITER_DEC
                    MATCHED_LITER_DEC
                    MATCHED_LITER_DEC
                    MATCHED_LITER_DEC
                    MATCHED_LITER_DEC
                    MATCHED_LITER_DEC
                    MATCHED_LITER_DEC
                }
#endif
            }

            dic[dicPos++] = (Byte) symbol;
            continue;
        }

        {
            UPDATE_1(prob);
            prob = probs + IsRep + state;

            IF_BIT_0(prob)
            {
                UPDATE_0(prob);
                state += kNumStates;
                prob = probs + LenCoder;
            }
            else
            {
                UPDATE_1(prob);
                /*
                // that case was checked before with kBadRepCode
                if (checkDicSize == 0 && processedPos == 0)
                  return SZ_ERROR_DATA;
                 */
                prob = probs + IsRepG0 + state;

                IF_BIT_0(prob)
                {
                    UPDATE_0(prob);
                    prob = probs + IsRep0Long + COMBINED_PS_STATE;

                    IF_BIT_0(prob)
                    {
                        UPDATE_0(prob);
                        dic[dicPos] = dic[dicPos - rep0 + (dicPos < rep0 ? dicBufSize : 0)];
                        dicPos++;
                        processedPos++;
                        state = state < kNumLitStates ? 9 : 11;
                        continue;
                    }
                    UPDATE_1(prob);
                }
                else
                {
                    UInt32 distance;
                    UPDATE_1(prob);
                    prob = probs + IsRepG1 + state;

                    IF_BIT_0(prob)
                    {
                        UPDATE_0(prob);
                        distance = rep1;
                    }
                    else
                    {
                        UPDATE_1(prob);
                        prob = probs + IsRepG2 + state;

                        IF_BIT_0(prob)
                        {
                            UPDATE_0(prob);
                            distance = rep2;
                        }
                        else
                        {
                            UPDATE_1(prob);
                            distance = rep3;
                            rep3 = rep2;
                        }
                        rep2 = rep1;
                    }
                    rep1 = rep0;
                    rep0 = distance;
                }
                state = state < kNumLitStates ? 8 : 11;
                prob = probs + RepLenCoder;
            }

#ifdef _LZMA_SIZE_OPT
            {
                unsigned lim, offset;
                CLzmaProb *probLen = prob + LenChoice;

                IF_BIT_0(probLen)
                {
                    UPDATE_0(probLen);
                    probLen = prob + LenLow + GET_LEN_STATE;
                    offset = 0;
                    lim = (1 << kLenNumLowBits);
                }
                else
                {
                    UPDATE_1(probLen);
                    probLen = prob + LenChoice2;

                    IF_BIT_0(probLen)
                    {
                        UPDATE_0(probLen);
                        probLen = prob + LenLow + GET_LEN_STATE + (1 << kLenNumLowBits);
                        offset = kLenNumLowSymbols;
                        lim = (1 << kLenNumLowBits);
                    }
                    else
                    {
                        UPDATE_1(probLen);
                        probLen = prob + LenHigh;
                        offset = kLenNumLowSymbols * 2;
                        lim = (1 << kLenNumHighBits);
                    }
                }
                TREE_DECODE(probLen, lim, len);
                len += offset;
            }
#else
            {
                CLzmaProb *probLen = prob + LenChoice;

                IF_BIT_0(probLen)
                {
                    UPDATE_0(probLen);
                    probLen = prob + LenLow + GET_LEN_STATE;
                    len = 1;
                    TREE_GET_BIT(probLen, len);
                    TREE_GET_BIT(probLen, len);
                    TREE_GET_BIT(probLen, len);
                    len -= 8;
                }
                else
                {
                    UPDATE_1(probLen);
                    probLen = prob + LenChoice2;

                    IF_BIT_0(probLen)
                    {
                        UPDATE_0(probLen);
                        probLen = prob + LenLow + GET_LEN_STATE + (1 << kLenNumLowBits);
                        len = 1;
                        TREE_GET_BIT(probLen, len);
                        TREE_GET_BIT(probLen, len);
                        TREE_GET_BIT(probLen, len);
                    }
                    else
                    {
                        UPDATE_1(probLen);
                        probLen = prob + LenHigh;
                        TREE_DECODE(probLen, (1 << kLenNumHighBits), len);
                        len += kLenNumLowSymbols * 2;
                    }
                }
            }
#endif

            if (state >= kNumStates)
            {
                UInt32 distance;
                prob = probs + PosSlot +
                       ((len < kNumLenToPosStates ? len : kNumLenToPosStates - 1) << kNumPosSlotBits);
                TREE_6_DECODE(prob, distance);
                if (distance >= kStartPosModelIndex)
                {
                    unsigned posSlot = (unsigned) distance;
                    unsigned numDirectBits = (unsigned)(((distance >> 1) - 1));
                    distance = (2 | (distance & 1));
                    if (posSlot < kEndPosModelIndex)
                    {
                        distance <<= numDirectBits;
                        prob = probs + SpecPos;
                        {
                            UInt32 m = 1;
                            distance++;
                            do
                            {
                                REV_BIT_VAR(prob, distance, m);
                            }
                            while (--numDirectBits);
                            distance -= m;
                        }
                    }
                    else
                    {
                        numDirectBits -= kNumAlignBits;
                        do
                        {
                            NORMALIZE
                            range >>= 1;

                            {
                                UInt32 t;
                                code -= range;
                                t = (0 - ((UInt32) code >> 31)); /* (UInt32)((Int32)code >> 31) */
                                distance = (distance << 1) + (t + 1);
                                code += range & t;
                            }
                            /*
                            distance <<= 1;
                            if (code >= range)
                            {
                              code -= range;
                              distance |= 1;
                            }
                             */
                        }
                        while (--numDirectBits);
                        prob = probs + Align;
                        distance <<= kNumAlignBits;
                        {
                            unsigned i = 1;
                            REV_BIT_CONST(prob, i, 1);
                            REV_BIT_CONST(prob, i, 2);
                            REV_BIT_CONST(prob, i, 4);
                            REV_BIT_LAST(prob, i, 8);
                            distance |= i;
                        }
                        if (distance == (UInt32) 0xFFFFFFFF)
                        {
                            len = kMatchSpecLenStart;
                            state -= kNumStates;
                            break;
                        }
                    }
                }

                rep3 = rep2;
                rep2 = rep1;
                rep1 = rep0;
                rep0 = distance + 1;
                state = (state < kNumStates + kNumLitStates) ? kNumLitStates : kNumLitStates + 3;
                if (distance >= (checkDicSize == 0 ? processedPos : checkDicSize))
                {
                    p->dicPos = dicPos;
                    return SZ_ERROR_DATA;
                }
            }

            len += kMatchMinLen;

            {
                SizeT rem;
                unsigned curLen;
                SizeT pos;

                if ((rem = limit - dicPos) == 0)
                {
                    p->dicPos = dicPos;
                    return SZ_ERROR_DATA;
                }

                curLen = ((rem < len) ? (unsigned) rem : len);
                pos = dicPos - rep0 + (dicPos < rep0 ? dicBufSize : 0);

                processedPos += (UInt32) curLen;

                len -= curLen;
                if (curLen <= dicBufSize - pos)
                {
                    Byte *dest = dic + dicPos;
                    ptrdiff_t src = (ptrdiff_t) pos - (ptrdiff_t) dicPos;
                    const Byte *lim = dest + curLen;
                    dicPos += (SizeT) curLen;
                    do
                        *(dest) = (Byte) * (dest + src);
                    while (++dest != lim);
                }
                else
                {
                    do
                    {
                        dic[dicPos++] = dic[pos];
                        if (++pos == dicBufSize)
                            pos = 0;
                    }
                    while (--curLen != 0);
                }
            }
        }
    }
    while (dicPos < limit && buf < bufLimit);

    NORMALIZE;

    p->buf = buf;
    p->range = range;
    p->code = code;
    p->remainLen = (UInt32) len;
    p->dicPos = dicPos;
    p->processedPos = processedPos;
    p->reps[0] = rep0;
    p->reps[1] = rep1;
    p->reps[2] = rep2;
    p->reps[3] = rep3;
    p->state = (UInt32) state;

    return SZ_OK;
}
#endif

static void MY_FAST_CALL LzmaDec_WriteRem(CLzmaDec *p, SizeT limit)
{
    if (p->remainLen != 0 && p->remainLen < kMatchSpecLenStart)
    {
        Byte *dic = p->dic;
        SizeT dicPos = p->dicPos;
        SizeT dicBufSize = p->dicBufSize;
        unsigned len = (unsigned) p->remainLen;
        SizeT rep0 = p->reps[0]; /* we use SizeT to avoid the BUG of VC14 for AMD64 */
        SizeT rem = limit - dicPos;
        if (rem < len)
            len = (unsigned)(rem);

        if (p->checkDicSize == 0 && p->prop.dicSize - p->processedPos <= len)
            p->checkDicSize = p->prop.dicSize;

        p->processedPos += (UInt32) len;
        p->remainLen -= (UInt32) len;
        while (len != 0)
        {
            len--;
            dic[dicPos] = dic[dicPos - rep0 + (dicPos < rep0 ? dicBufSize : 0)];
            dicPos++;
        }
        p->dicPos = dicPos;
    }
}


#define kRange0 0xFFFFFFFF
#define kBound0 ((kRange0 >> kNumBitModelTotalBits) << (kNumBitModelTotalBits - 1))
#define kBadRepCode (kBound0 + (((kRange0 - kBound0) >> kNumBitModelTotalBits) << (kNumBitModelTotalBits - 1)))
#if kBadRepCode != (0xC0000000 - 0x400)
#error Stop_Compiling_Bad_LZMA_Check
#endif

static int MY_FAST_CALL LzmaDec_DecodeReal2(CLzmaDec *p, SizeT limit, const Byte *bufLimit)
{
    do
    {
        SizeT limit2 = limit;
        if (p->checkDicSize == 0)
        {
            UInt32 rem = p->prop.dicSize - p->processedPos;
            if (limit - p->dicPos > rem)
                limit2 = p->dicPos + rem;

            if (p->processedPos == 0)
                if (p->code >= kBadRepCode)
                    return SZ_ERROR_DATA;
        }

        RINOK(LZMA_DECODE_REAL(p, limit2, bufLimit));

        if (p->checkDicSize == 0 && p->processedPos >= p->prop.dicSize)
            p->checkDicSize = p->prop.dicSize;

        LzmaDec_WriteRem(p, limit);
    }
    while (p->dicPos < limit && p->buf < bufLimit && p->remainLen < kMatchSpecLenStart);

    return 0;
}

typedef enum
{
    DUMMY_ERROR, /* unexpected end of input stream */
    DUMMY_LIT,
    DUMMY_MATCH,
    DUMMY_REP
} ELzmaDummy;

static ELzmaDummy LzmaDec_TryDummy(const CLzmaDec *p, const Byte *buf, SizeT inSize)
{
    UInt32 range = p->range;
    UInt32 code = p->code;
    const Byte *bufLimit = buf + inSize;
    const CLzmaProb *probs = GET_PROBS;
    unsigned state = (unsigned) p->state;
    ELzmaDummy res;

    {
        const CLzmaProb *prob;
        UInt32 bound;
        unsigned ttt;
        unsigned posState = CALC_POS_STATE(p->processedPos, (1 << p->prop.pb) - 1);

        prob = probs + IsMatch + COMBINED_PS_STATE;

        IF_BIT_0_CHECK(prob)
        {
            UPDATE_0_CHECK

            /* if (bufLimit - buf >= 7) return DUMMY_LIT; */

            prob = probs + Literal;
            if (p->checkDicSize != 0 || p->processedPos != 0)
                prob += ((UInt32) LZMA_LIT_SIZE *
                         ((((p->processedPos) & ((1 << (p->prop.lp)) - 1)) << p->prop.lc) +
                          (p->dic[(p->dicPos == 0 ? p->dicBufSize : p->dicPos) - 1] >> (8 - p->prop.lc))));

            if (state < kNumLitStates)
            {
                unsigned symbol = 1;
                do
                {
                    GET_BIT_CHECK(prob + symbol, symbol)
                }
                while (symbol < 0x100);
            }
            else
            {
                unsigned matchByte = p->dic[p->dicPos - p->reps[0] +
                                                      (p->dicPos < p->reps[0] ? p->dicBufSize : 0)];
                unsigned offs = 0x100;
                unsigned symbol = 1;
                do
                {
                    unsigned bit;
                    const CLzmaProb *probLit;
                    matchByte += matchByte;
                    bit = offs;
                    offs &= matchByte;
                    probLit = prob + (offs + bit + symbol);
                    GET_BIT2_CHECK(probLit, symbol, offs ^= bit;,;)
                }
                while (symbol < 0x100);
            }
            res = DUMMY_LIT;
        }
        else
        {
            unsigned len;
            UPDATE_1_CHECK;

            prob = probs + IsRep + state;

            IF_BIT_0_CHECK(prob)
            {
                UPDATE_0_CHECK;
                state = 0;
                prob = probs + LenCoder;
                res = DUMMY_MATCH;
            }
            else
            {
                UPDATE_1_CHECK;
                res = DUMMY_REP;
                prob = probs + IsRepG0 + state;

                IF_BIT_0_CHECK(prob)
                {
                    UPDATE_0_CHECK;
                    prob = probs + IsRep0Long + COMBINED_PS_STATE;

                    IF_BIT_0_CHECK(prob)
                    {
                        UPDATE_0_CHECK;
                        NORMALIZE_CHECK;
                        return DUMMY_REP;
                    }
                    else
                    {
                        UPDATE_1_CHECK;
                    }
                }
                else
                {
                    UPDATE_1_CHECK;
                    prob = probs + IsRepG1 + state;

                    IF_BIT_0_CHECK(prob)
                    {
                        UPDATE_0_CHECK;
                    }
                    else
                    {
                        UPDATE_1_CHECK;
                        prob = probs + IsRepG2 + state;

                        IF_BIT_0_CHECK(prob)
                        {
                            UPDATE_0_CHECK;
                        }
                        else
                        {
                            UPDATE_1_CHECK;
                        }
                    }
                }
                state = kNumStates;
                prob = probs + RepLenCoder;
            }
            {
                unsigned limit, offset;
                const CLzmaProb *probLen = prob + LenChoice;

                IF_BIT_0_CHECK(probLen)
                {
                    UPDATE_0_CHECK;
                    probLen = prob + LenLow + GET_LEN_STATE;
                    offset = 0;
                    limit = 1 << kLenNumLowBits;
                }
                else
                {
                    UPDATE_1_CHECK;
                    probLen = prob + LenChoice2;

                    IF_BIT_0_CHECK(probLen)
                    {
                        UPDATE_0_CHECK;
                        probLen = prob + LenLow + GET_LEN_STATE + (1 << kLenNumLowBits);
                        offset = kLenNumLowSymbols;
                        limit = 1 << kLenNumLowBits;
                    }
                    else
                    {
                        UPDATE_1_CHECK;
                        probLen = prob + LenHigh;
                        offset = kLenNumLowSymbols * 2;
                        limit = 1 << kLenNumHighBits;
                    }
                }
                TREE_DECODE_CHECK(probLen, limit, len);
                len += offset;
            }

            if (state < 4)
            {
                unsigned posSlot;
                prob = probs + PosSlot +
                       ((len < kNumLenToPosStates - 1 ? len : kNumLenToPosStates - 1) <<
                        kNumPosSlotBits);
                TREE_DECODE_CHECK(prob, 1 << kNumPosSlotBits, posSlot);
                if (posSlot >= kStartPosModelIndex)
                {
                    unsigned numDirectBits = ((posSlot >> 1) - 1);

                    /* if (bufLimit - buf >= 8) return DUMMY_MATCH; */

                    if (posSlot < kEndPosModelIndex)
                    {
                        prob = probs + SpecPos + ((2 | (posSlot & 1)) << numDirectBits);
                    }
                    else
                    {
                        numDirectBits -= kNumAlignBits;
                        do
                        {
                            NORMALIZE_CHECK
                            range >>= 1;
                            code -= range & (((code - range) >> 31) - 1);
                            /* if (code >= range) code -= range; */
                        }
                        while (--numDirectBits);
                        prob = probs + Align;
                        numDirectBits = kNumAlignBits;
                    }
                    {
                        unsigned i = 1;
                        unsigned m = 1;
                        do
                        {
                            REV_BIT_CHECK(prob, i, m);
                        }
                        while (--numDirectBits);
                    }
                }
            }
        }
    }
    NORMALIZE_CHECK;
    return res;
}

void LzmaDec_InitDicAndState(CLzmaDec *p, BoolInt initDic, BoolInt initState)
{
    p->remainLen = kMatchSpecLenStart + 1;
    p->tempBufSize = 0;

    if (initDic)
    {
        p->processedPos = 0;
        p->checkDicSize = 0;
        p->remainLen = kMatchSpecLenStart + 2;
    }
    if (initState)
        p->remainLen = kMatchSpecLenStart + 2;
}

void LzmaDec_Init(CLzmaDec *p)
{
    p->dicPos = 0;
    LzmaDec_InitDicAndState(p, True, True);
}

SRes LzmaDec_DecodeToDic(CLzmaDec *p, SizeT dicLimit, const Byte *src, SizeT *srcLen,
                         ELzmaFinishMode finishMode, ELzmaStatus *status)
{
    SizeT inSize = *srcLen;
    (*srcLen) = 0;

    *status = LZMA_STATUS_NOT_SPECIFIED;
    if (p->remainLen > kMatchSpecLenStart)
    {
        for (; inSize > 0 && p->tempBufSize < RC_INIT_SIZE; (*srcLen)++, inSize--)
            p->tempBuf[p->tempBufSize++] = *src++;
        if (p->tempBufSize != 0 && p->tempBuf[0] != 0)
            return SZ_ERROR_DATA;
        if (p->tempBufSize < RC_INIT_SIZE)
        {
            *status = LZMA_STATUS_NEEDS_MORE_INPUT;
            return SZ_OK;
        }
        p->code =
            ((UInt32) p->tempBuf[1] << 24)
            | ((UInt32) p->tempBuf[2] << 16)
            | ((UInt32) p->tempBuf[3] << 8)
            | ((UInt32) p->tempBuf[4]);
        p->range = 0xFFFFFFFF;
        p->tempBufSize = 0;

        if (p->remainLen > kMatchSpecLenStart + 1)
        {
            SizeT numProbs = LzmaProps_GetNumProbs(&p->prop);
            SizeT i;
            CLzmaProb *probs = p->probs;
            for (i = 0; i < numProbs; i++)
                probs[i] = kBitModelTotal >> 1;
            p->reps[0] = p->reps[1] = p->reps[2] = p->reps[3] = 1;
            p->state = 0;
        }

        p->remainLen = 0;
    }
    LzmaDec_WriteRem(p, dicLimit);

    while (p->remainLen != kMatchSpecLenStart)
    {
        int checkEndMarkNow = 0;

        if (p->dicPos >= dicLimit)
        {
            if (p->remainLen == 0 && p->code == 0)
            {
                *status = LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK;
                return SZ_OK;
            }
            if (finishMode == LZMA_FINISH_ANY)
            {
                *status = LZMA_STATUS_NOT_FINISHED;
                return SZ_OK;
            }
            if (p->remainLen != 0)
            {
                *status = LZMA_STATUS_NOT_FINISHED;
                return SZ_ERROR_DATA;
            }
            checkEndMarkNow = 1;
        }

        if (p->tempBufSize == 0)
        {
            SizeT processed;
            const Byte *bufLimit;
            if (inSize < LZMA_REQUIRED_INPUT_MAX || checkEndMarkNow)
            {
                int dummyRes = LzmaDec_TryDummy(p, src, inSize);
                if (dummyRes == DUMMY_ERROR)
                {
                    memcpy(p->tempBuf, src, inSize);
                    p->tempBufSize = (unsigned) inSize;
                    (*srcLen) += inSize;
                    *status = LZMA_STATUS_NEEDS_MORE_INPUT;
                    return SZ_OK;
                }
                if (checkEndMarkNow && dummyRes != DUMMY_MATCH)
                {
                    *status = LZMA_STATUS_NOT_FINISHED;
                    return SZ_ERROR_DATA;
                }
                bufLimit = src;
            }
            else
                bufLimit = src + inSize - LZMA_REQUIRED_INPUT_MAX;
            p->buf = src;
            if (LzmaDec_DecodeReal2(p, dicLimit, bufLimit) != 0)
                return SZ_ERROR_DATA;
            processed = (SizeT)(p->buf - src);
            (*srcLen) += processed;
            src += processed;
            inSize -= processed;
        }
        else
        {
            unsigned rem = p->tempBufSize, lookAhead = 0;
            while (rem < LZMA_REQUIRED_INPUT_MAX && lookAhead < inSize)
                p->tempBuf[rem++] = src[lookAhead++];
            p->tempBufSize = rem;
            if (rem < LZMA_REQUIRED_INPUT_MAX || checkEndMarkNow)
            {
                int dummyRes = LzmaDec_TryDummy(p, p->tempBuf, (SizeT) rem);
                if (dummyRes == DUMMY_ERROR)
                {
                    (*srcLen) += (SizeT) lookAhead;
                    *status = LZMA_STATUS_NEEDS_MORE_INPUT;
                    return SZ_OK;
                }
                if (checkEndMarkNow && dummyRes != DUMMY_MATCH)
                {
                    *status = LZMA_STATUS_NOT_FINISHED;
                    return SZ_ERROR_DATA;
                }
            }
            p->buf = p->tempBuf;
            if (LzmaDec_DecodeReal2(p, dicLimit, p->buf) != 0)
                return SZ_ERROR_DATA;

            {
                unsigned kkk = (unsigned)(p->buf - p->tempBuf);
                if (rem < kkk)
                    return SZ_ERROR_FAIL; /* some internal error */
                rem -= kkk;
                if (lookAhead < rem)
                    return SZ_ERROR_FAIL; /* some internal error */
                lookAhead -= rem;
            }
            (*srcLen) += (SizeT) lookAhead;
            src += lookAhead;
            inSize -= (SizeT) lookAhead;
            p->tempBufSize = 0;
        }
    }

    if (p->code != 0)
        return SZ_ERROR_DATA;
    *status = LZMA_STATUS_FINISHED_WITH_MARK;
    return SZ_OK;
}

SRes LzmaDec_DecodeToBuf(CLzmaDec *p, Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen, ELzmaFinishMode finishMode, ELzmaStatus *status)
{
    SizeT outSize = *destLen;
    SizeT inSize = *srcLen;
    *srcLen = *destLen = 0;
    for (;;)
    {
        SizeT inSizeCur = inSize, outSizeCur, dicPos;
        ELzmaFinishMode curFinishMode;
        SRes res;

        if (p->dicPos == p->dicBufSize)
            p->dicPos = 0;
        dicPos = p->dicPos;

        if (outSize > p->dicBufSize - dicPos)
        {
            outSizeCur = p->dicBufSize;
            curFinishMode = LZMA_FINISH_ANY;
        }
        else
        {
            outSizeCur = dicPos + outSize;
            curFinishMode = finishMode;
        }

        res = LzmaDec_DecodeToDic(p, outSizeCur, src, &inSizeCur, curFinishMode, status);
        src += inSizeCur;
        inSize -= inSizeCur;
        *srcLen += inSizeCur;
        outSizeCur = p->dicPos - dicPos;
        memcpy(dest, p->dic + dicPos, outSizeCur);
        dest += outSizeCur;
        outSize -= outSizeCur;
        *destLen += outSizeCur;
        if (res != 0)
            return res;
        if (outSizeCur == 0 || outSize == 0)
            return SZ_OK;
    }
}

void LzmaDec_FreeProbs(CLzmaDec *p, ISzAllocPtr alloc)
{
    ISzAlloc_Free(alloc, p->probs);
    p->probs = NULL;
}

static void LzmaDec_FreeDict(CLzmaDec *p, ISzAllocPtr alloc)
{
    ISzAlloc_Free(alloc, p->dic);
    p->dic = NULL;
}

void LzmaDec_Free(CLzmaDec *p, ISzAllocPtr alloc)
{
    LzmaDec_FreeProbs(p, alloc);
    LzmaDec_FreeDict(p, alloc);
}

SRes LzmaProps_Decode(CLzmaProps *p, const Byte *data, unsigned size)
{
    UInt32 dicSize;
    Byte d;

    if (size < LZMA_PROPS_SIZE)
        return SZ_ERROR_UNSUPPORTED;
    else
        dicSize = data[1] | ((UInt32) data[2] << 8) | ((UInt32) data[3] << 16) | ((UInt32) data[4] << 24);

    if (dicSize < LZMA_DIC_MIN)
        dicSize = LZMA_DIC_MIN;
    p->dicSize = dicSize;

    d = data[0];
    if (d >= (9 * 5 * 5))
        return SZ_ERROR_UNSUPPORTED;

    p->lc = (Byte)(d % 9);
    d /= 9;
    p->pb = (Byte)(d / 5);
    p->lp = (Byte)(d % 5);

    return SZ_OK;
}

static SRes LzmaDec_AllocateProbs2(CLzmaDec *p, const CLzmaProps *propNew, ISzAllocPtr alloc)
{
    UInt32 numProbs = LzmaProps_GetNumProbs(propNew);
    if (!p->probs || numProbs != p->numProbs)
    {
        LzmaDec_FreeProbs(p, alloc);
        p->probs = (CLzmaProb *) ISzAlloc_Alloc(alloc, numProbs * sizeof(CLzmaProb));
        if (!p->probs)
            return SZ_ERROR_MEM;
        p->probs_1664 = p->probs + 1664;
        p->numProbs = numProbs;
    }
    return SZ_OK;
}

SRes LzmaDec_AllocateProbs(CLzmaDec *p, const Byte *props, unsigned propsSize, ISzAllocPtr alloc)
{
    CLzmaProps propNew;
    RINOK(LzmaProps_Decode(&propNew, props, propsSize));
    RINOK(LzmaDec_AllocateProbs2(p, &propNew, alloc));
    p->prop = propNew;
    return SZ_OK;
}

SRes LzmaDec_Allocate(CLzmaDec *p, const Byte *props, unsigned propsSize, ISzAllocPtr alloc)
{
    CLzmaProps propNew;
    SizeT dicBufSize;
    RINOK(LzmaProps_Decode(&propNew, props, propsSize));
    RINOK(LzmaDec_AllocateProbs2(p, &propNew, alloc));

    {
        UInt32 dictSize = propNew.dicSize;
        SizeT mask = ((UInt32) 1 << 12) - 1;
        if (dictSize >= ((UInt32) 1 << 30)) mask = ((UInt32) 1 << 22) - 1;
        else if (dictSize >= ((UInt32) 1 << 22)) mask = ((UInt32) 1 << 20) - 1;
        ;
        dicBufSize = ((SizeT) dictSize + mask) & ~mask;
        if (dicBufSize < dictSize)
            dicBufSize = dictSize;
    }

    if (!p->dic || dicBufSize != p->dicBufSize)
    {
        LzmaDec_FreeDict(p, alloc);
        p->dic = (Byte *) ISzAlloc_Alloc(alloc, dicBufSize);
        if (!p->dic)
        {
            LzmaDec_FreeProbs(p, alloc);
            return SZ_ERROR_MEM;
        }
    }
    p->dicBufSize = dicBufSize;
    p->prop = propNew;
    return SZ_OK;
}

SRes LzmaDecode(Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen,
                const Byte *propData, unsigned propSize, ELzmaFinishMode finishMode,
                ELzmaStatus *status, ISzAllocPtr alloc)
{
    CLzmaDec p;
    SRes res;
    SizeT outSize = *destLen, inSize = *srcLen;
    *destLen = *srcLen = 0;
    *status = LZMA_STATUS_NOT_SPECIFIED;
    if (inSize < RC_INIT_SIZE)
        return SZ_ERROR_INPUT_EOF;
    LzmaDec_Construct(&p);
    RINOK(LzmaDec_AllocateProbs(&p, propData, propSize, alloc));
    p.dic = dest;
    p.dicBufSize = outSize;
    LzmaDec_Init(&p);
    *srcLen = inSize;
    res = LzmaDec_DecodeToDic(&p, outSize, src, srcLen, finishMode, status);
    *destLen = p.dicPos;
    if (res == SZ_OK && *status == LZMA_STATUS_NEEDS_MORE_INPUT)
        res = SZ_ERROR_INPUT_EOF;
    LzmaDec_FreeProbs(&p, alloc);
    return res;
}
